The present invention relates generally to apparatus and methods for the temporary captive storage of live gamefish and other similar aquatic animals. More particularly, the present invention relates to an improved livewell apparatus and method for use in a recreational fishing boat and similar watercraft.
Over recent years, recreational and sport fishing has grown considerably in popularity as well as sophistication with the advent of more scientifically-designed fishing equipment and techniques. As part of this trend, various technical and design improvements in recreational fishing boats have evolved, one such improvement being the provision of an inboard water reservoir or tank, commonly referred to as a "livewell," for containing a quantity of water in which to store captured fish to maintain them alive for a reasonable period of time in captivity. With the proliferation in past years of tournament fishing events with relatively sizable monetary awards to winning participants, the provision and reliability of a livewell in a fishing boat is of considerable importance to the serious fisherman in that typical tournament fishing rules provide for some penalization as to dead fish and, moreover, a fish normally loses several ounces of weight upon its death as a result of the natural emptying of the fish's waste cavities, scale loss and similar reasons.
Conventional livewells provided in modern recreational fishing boats typically provide a battery-operated electric water pump for selectively filling the tank with water from the ambient body of water in which the boat is being operated and an overflow discharge line to establish a maximum level of water in the tank to prevent overfilling thereof. More sophisticated livewells also provide a pump-operated aeration system for withdrawing water contained in the tank and spraying it in return into the tank to replenish any oxygen from the water consumed by fish stored therein. An electric timing device may be provided to periodically actuate and de-actuate the aeration system. In addition, it is normally necessary in practice to periodically operate the fill pump for the tank to discharge through the overflow line fish scales, slime secretions and waste discharges which captured fish typically expel in their normally excited state after being placed in the livewell. a timing device may therefore also be provided in conjunction with the livewell fill pump to automatically perform this overflow dischage periodically.
Despite the above-described provisions in the most sophisticated conventional livewells for maintaining a relatively clean body of contained water in the livewell and for continuously aerating the water, experience has shown that even the most sophisticated livewells are incapable of reliably maintaining captured fish alive for more than one to three hours. The severity of this problem can be affected by numerous factors, including the particular species of fish involved, the condition and excited nature of the fish, the condition of the water utilized in the livewell including for instance its oxygen content and temperature, etc., all of which make it difficult to evaluate and determine the reason or reasons for this problem.